First off, every headline explaining market movement this morning is (or will be) focusing on positive outcomes from an early stage vaccine trial.  Those headlines hit at 7:30am ET and that's right about the time bond yields and stock prices began moving higher together.    But close only counts in horse shoes and hand grenades.  10 minutes is an eternity when it comes to markets reacting to such an overt and highly anticipated market mover, yet that's exactly how long stocks and bonds waited this time.

Why are we seeing this 10 minute gap?  

That's a really good question.  At the very least, it suggests the early weakness may not be as simple as a basic reaction function of the vaccine news.  Perhaps our ability to ask such a question helps explain why bonds have been resilient after the first few bps of weakness.  10yr yields are still higher on the day, but have come off their previous highs of .682 and are currently trading about 1bp lower.  2.0 MBS are nearly unchanged on the day after being down several ticks earlier.